BOU a , 
of the voyage. On which account, though 
the interest be greater than what the law 
commonly allows, yet it is not usury, be- 
cause the money being furnished at the 
lender’s hazard, if the ship perishes, he shares 
in the loss. 
BOTTON Y , a cross bottony,in heraldry, 
terminates at each end in three buds, knots, 
or buttons, resembling, in some measure, the 
three-leaved grass. 
BOTTS. See Oestris. 
BOUCHE of court, the privilege of 
having meat and drink at court, scot-free. 
This privilege is sometimes only extended 
to bread, beer, and wine ; and was anci- 
ently in use as well in the houses of noble- 
men as in the king’s court. 
BOUGUER (Peter), in biography, a 
celebrated French mathematician, born at 
Croisci in, Lower Bretagne, in February, 
1698. His father, John, was professor of 
hydrography, and author of “ A Complete 
Treatise on Navigation.” Young Bouguer 
learnt mathematics of his father, from the 
time he was able to speak, and thus be- 
came a proficient in those sciences while 
lie was yet a child. He was sent very early 
to the Jesuits’ college at Vannes, where he 
had the honour to instruct his regent in the 
mathematics, at eleven years of age. Two 
years after this he had a public contest 
with a professor of mathematics, upon a 
proposition which the latter had advanced 
erroneously ; and he triumphed over him ; 
upon which the professor, unable to bear 
the disgrace, left the country. Upon the 
death of his father, he was appointed to 
succeed in his office of hydrographer, after 
a public examination of his qualifications ; 
being then only fifteen years of age ; an oc- 
cupation which he discharged with great 
respect and dignity at that early age. In 
1727, at the age of twenty-nine, he obtain- 
ed the prize proposed by the Academy of 
Sciences, for the best way of masting of 
ships. Hiis first success of Bouguer was 
soon after followed by two others of the 
same kind; he successively gained the prizes 
of 1729 and 1731 ; the former, for the best 
manner of observing at sea the height of the 
stars, and the latter, for the most advanta- 
geous way of observing the declination of 
the magnetic needle, or the variation of the 
compass. 
In 1730, he was removed from the port 
of Croisci to that of Havre, which brought 
him into a nearer connection with the Aca- 
demy of Sciences, in which he obtained, in 
BOO 
17 ol, the place of associate geometrician, 
vacant by the promotion of Maupertuis to 
that of pensioner ; and in 1735 he was pro- 
moted to the office of pensioner-astrono- 
mer. The same year he was sent on the 
commission to South America^ along with 
Messieurs Godin, Condamine, and Jussieu, 
to determine the measure of the degrees of 
the meridian, and the figure of the earth. 
In this painful and troublesome business, 
of ten years duration, chiefly among the 
lofty Cordelier mountains, our author deter- 
mined many other new circumstances, be- 
side the main object of the voyage ; such as 
the expansion and contraction of metals 
and other substances, by the sudden and al- 
ternate changes of heat and cold among 
those mountains ; observations on the re* 
fraction of the atmosphere from the tops of 
the same, with the singular phenomenon of 
the sudden increase of the refraction, when 
the star can be observed below the line of 
the level ; the laws of the density of the air 
at different heights, from observations made 
at different points of these enormous moun- 
tains; a determination that the mountains 
have an effect upon a plummet, though he 
did not assign the exact quantity of it; a 
method of estimating the errors committed 
by navigators in determining their route ; a 
new construction of the log for measuring a 
ship’s way; with several other useful im- 
provements. 
Other inventions of Bouguer, made upon 
different occasions, were as follow : the he- 
liometer, being a telescope with two object 
glasses, affording a good method of mea- 
suring the diameters of the larger planets 
with ease and exactness : his researches 
on the figure in which two lines or two 
long ranges of parallel trees appear: his 
experiments on the famous reciproca- 
tion of the pendulum; and those upon 
the manner of measuring the force of the 
light ; &c. Ac. 
The close application which Bouguer 
gave to study, undermined his health, and 
terminated his life the 15th of August, 1758, 
at 60 years of age. His chief works, that 
have been published, are, 1 . “ The Figure 
of the Earth, determined by the observa- 
tions made in South America;” 1749 , in 
4to. 2 . “ Treatise on Navigation and ’pi- 
lotage ;” Paris, 1752, in 4to. This work 
has been abridged by M. La Caille, in one 
volume, 8vo. 1768. 3. “A Treatise on 
Ships, their Construction and Motions ;” in 
4to., 1756. 4.. “An Optical Treatise on 
the Gradation of Light;” first in 1729; then 
a new edition in 1760, in 4to. and a great’ 
